Electronics Forum | Thu Jun 13 14:41:40 EDT 2024 | tommy_magyar
Hi David, In one of my previous jobs I worked as an AOI/AXI process engineer and we had a set target of 75% FPY. This means that 75% of the boards at IPC Class 3 standards would not have a single false call. This also means you would need to set y
Electronics Forum | Tue Jan 18 20:31:10 EST 2000 | WDavidson
It makes a difference what the normalizer is. We calculate solder ppm and placement ppm separately for each assembly. Solder ppm = #solder defects*1E6/(Qty boards*#solder joints per board). For us this number is easily less than 50 and sometimes
Electronics Forum | Thu Jul 14 11:04:53 EDT 2005 | dougs
yes SPC can be used on a wave solder machine, you should use a c-chart to monitor the amount of defects per board or group of boards, this will let you know if your process is stable, as you improve your process you should re-calculate your UCL, hope
Electronics Forum | Mon Jan 29 16:04:29 EST 2007 | BillW
Thanks Russ and John, To clarify defects when manufacturing a PCBA, I use (2) groups of defect categories, one for components and one for solder joints. These can be calculated separately or combined A component defect could be: Missing, Miss-alig
Electronics Forum | Fri Jun 29 12:47:25 EDT 2012 | deanm
We are experiencing widely varying First Pass Yields for selective soldering. Some boards are near 100% while others are less than 50% depending on the pitch and general complexity of the board. Question: If you are running 100 boards through your s
Electronics Forum | Wed Jan 17 18:08:51 EST 2007 | John S.
We use a fairly simple system. IPC put out standards 7912A and 9261A to define opportunities. Basicly the "number of components" + "number of solder joints" = "number of opportunities." Some six sigma benchmarking studies indicated "Sigma Level" =
Electronics Forum | Tue Nov 20 12:21:02 EST 2001 | mparker
First, determine a standard to follow. IPC/EIA J-STD-001C "Requirements for Soldered Electrical and Electronic Assemblies" is most current for electronic assemblies. Second, by your customers spec. determine which class of the standard to apply. Use
Electronics Forum | Tue Mar 04 18:05:03 EST 2003 | msivigny
Hello Maribel, One way you justify the use of an AOI is to calculate how many defects the system will potentially detect before reflow, associate a repair cost per defect and make the calculation. For an AOI to be effective in this regard, it must sc
Electronics Forum | Tue Mar 30 22:19:02 EST 1999 | dean
| Does any have any reports on competive Component PPM levels for world class manufacturers ?? I would also like to get any information on the fault spectrum for component mounting. | | Generally, it is accepted that world class is below 100 DPMO (
Electronics Forum | Fri Aug 26 21:23:38 EDT 2005 | Jes�s Salinas
Hello , In our case we take the results from the repair station. Each test station has its own repair station so from there we count the process defects : placement and printing. The formula used to calculate PPM = DEFECTS / (PARTS PER BOARD x UNITS
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